bitbonkNov 16, 2022

Did you know you can inject languages into string literals with a comment in #JetBrainsRider? It will enable basic syntax highlighting and *some* code completion in the string literal. Additionally it will give you warnings if the string literal is not valid in the chosen language.

In .NET 7 you will also be able to use the StringSyntaxAttribute https://learn.microsoft.com/dotnet/api/system.diagnostics.codeanalysis.stringsyntaxattribute which also works in #VisualStudio. But attributes can't be used everywhere (e.g. for local variables).

#dotnet @dotnet

StringSyntaxAttribute Class (System.Diagnostics.CodeAnalysis)

Specifies the syntax used in a string.

Show threadJames HartNov 16, 2022

@bitbonk @dotnet makes me a little sad how close this is to an embedded language-typed-string-literal though.

Like, we’re almost at

JSONObject j = $JSON“””
{ “foo”:”bar” }
“””

With a pluggable compile time validation and parse…

Show threadKhalid ⚡Nov 16, 2022

@james_a_hart @bitbonk @dotnet so Rider can have attributes on method parameters to signal to the editor the intended language. I guess you could extend that attribute to types as well.

In your example, JSONObject casts from string would implicitly trigger the behavior in IDE.

Show threadJames HartNov 16, 2022

@khalidabuhakmeh @bitbonk @dotnet yeah, I’m just wishcoding a full C# language/compiler feature here.

If I’ve got a string literal in my code which my IDE is guaranteeing contains valid JSON, I’d love to have the compiler back that guarantee up too. And if it’s *validating* it, why not also manifest it as a more interesting object than a mere ‘string’ while you’re at it? Like:

Date christmas = $Date”2022/12/25”;

With compile time warnings, and no runtime parse…

Show threadKhalid ⚡Nov 16, 2022
@james_a_hart @bitbonk @dotnet a source generator could do this (I think).
Show threadJames HartNov 16, 2022

@khalidabuhakmeh @bitbonk @dotnet I suspect so.

There goes my weekend.

Show threadbitbonk
@james_a_hart @khalidabuhakmeh @dotnet I doubt that a source generator can do the “manifesting in a more interring object” part but it sure could validate the content of a string literal. But be careful: This type of analysis can become expensive and may degrade the overall IDE performance. Source generators are executed upon every keystroke (with all kinds of optimizations of course).
Nov 16, 2022 at 4:22pmToot!
Show threadKhalid ⚡Nov 16, 2022
@bitbonk @james_a_hart @dotnet the source generator can both generate the methods and then read the string literals causing build failures. A Roslyn analyzer might be smarter though tbh.